>One thing is that we cannot delete messages if they already have replies.

It is technically possible, basically what is done is the text is zapped, and replaced with "This message has been deleted." The "Delete" button is just an automated way of clearing out your own post instead of editing it out manually. It can produce a little thread continuity confusion, as Mike noted, of course.

The "non-reply" window of time for edits is not a bad idea - most of the time I re-edit my messages, it is quite soon after I post, and realize a stupid typo, for example, or left out a critical bit of information, also.

I realize we have Previews (on both forums) for this, but I really hate using the feature (too time-consuming), and only do in cases of tricky HTML I want to check. And more than once I have lost my posts after Preview for one problem or another...